2Heat charcoal 20 minutes or heat both sides of gas grill on High for 10 minutes with lid closed.

3Meanwhile, place mustard seeds and black peppercorns in a sealable 1-quart plastic bag; crush with a rolling pin or meat mallet until fine. Crush garlic into a small bowl. Blend with pepper mixture, sugar, salt and mustard powder. Stir in oil to make a paste. Pat over tops of lamb racks.

4Bank charcoal on one side of grill or turn off heat on one side of gas grill. Place lamb on cool side of brill, bone-side down. Close lid and cook lamb 30 to 40 minutes. (Add coals to keep chamber air temperature at 425 degrees F, if necessary.)

6Oven Cooking Method: Heat oven to 425 degrees F. Follow all preparation instructions described above. Instead of heating charcoal and placing on grill, place lamb on a rack on foil-lined baking sheet. Roast 30 to 40 minutes. Test doneness with a meat thermometer using the same temperatures described above as your guideline.